RIO DE JANEIRO — There is no more familiar sight, every fourth summer, than this: Michael Phelps, bare-chested and flexing on a pool deck, thrusting a sinewy arm into the air and letting out a wail. No Olympic athlete has been in such a position more frequently. And yet here, Sunday night, it somehow felt new again.

“When I was on the block, I honestly felt like my heart was going to explode out of my chest,” Phelps said. “I was so hyped tonight.”

By now, at 31, Phelps is a one-man Olympic hype machine. He began seizing the Games and making them his own as a teenager a dozen years ago, when he won his first medal in Athens. Sunday night, that process began again at these, his fifth Olympics. It takes four swimmers to win a relay. But the signature moment in the men’s 4x100-meter freestyle came from the signature Olympian, the only athlete who would simultaneously open his Olympic swim meet and extend his unassailable Olympic legend.

The American team of Caeleb Dressel, Phelps, Ryan Held and anchor Nathan Adrian delivered a performance that was dominant collectively and individually. They took gold — the 19th gold of Phelps’s career, his 23rd medal overall, both records that could grow further — by crushing teams from France and Australia, each of whom had designs on gold themselves. Yet on an extraordinary night at Olympic Aquatics Stadium, a night on which three world records were set, the Americans won in 3:09.92 — comfortably ahead of silver-winning France (0.61 seconds back), with bronze-winning Australia an afterthought, 1.45 seconds in arrears.

“It feels good to start getting toward the end how I want to,” Phelps said.

How to call the 4x100 the featured event when so much else happened Sunday? The world record slayers: Bethesda’s Katie Ledecky in the women’s 400 freestyle, Sweden’s Sarah Sjostrom in the women’s 100 butterfly and Great Britain’s Adam Peaty in the men’s 100 breaststroke. The United States also picked up three bronzes — Dana Vollmer behind Sjostrom, Cody Miller behind Peaty and Leah Smith, from the University of Virginia, behind Ledecky — to give the team eight medals in the pool, more than twice as many as the next-closest nation after two nights.

But the star power, the competition, the characters — the relay had it all. The event has provided some of the most indelible moments in the history not just of swimming, but of the Olympics, full stop. None, of course, was more significant than Jason Lezak’s transcendent swim as the American anchor eight years ago in Beijing, when he saved Phelps’s quest for an unprecedented eight golds in a single Games. Four years ago, the French — who Lezak had stalked down — gained retribution, with Yannick Agnel stalking down Ryan Lochte on the anchor leg, leaving the U.S., and Phelps, with silver. In nine Olympic relays to that point, it was just the second time Phelps hadn’t taken gold.

Indeed, that indelible gold from 2008, and an ensuing victory the following year at world championships, were the last time the Americans had won the event at either the Olympics or worlds.

“It’s been tough,” said Adrian, the reigning Olympic champion in the 100 free. “We’re a country that’s so deep, that’s so deep in the sprints. . . . We’ve had that depth, we just hadn’t had those four guys together at the same time.”

That Phelps was one of the four was never guaranteed. He did not swim the 100 freestyle at the U.S. trials. He had to earn his way into the spot, swimming at night, by what he showed in training camp. A week ago, Adrian said, the U.S. team held a time trial.

American swimmers won a combined 31 medals at the London games in 2012, the most of any sport for Team USA. Meet the athletes who will be competing in Rio. (Jayne Orenstein/The Washington Post)

“He proved that he belonged there,” Adrian said.

The only thing that remained to be proved: a swim when it mattered. This is where Phelps is at his best, though, when there’s competitive blood in the water. Dressel led off this race, and though he trailed the team from Brazil when he handed off to Phelps, the Americans were in the process of taking control.

The control was irrefutable, though, after Phelps swam his first 50 meters. He flipped and pulled off a powerful, athletic turn. “I thought my kick-out was great,” he said, “and I just wanted to hammer it.” When he finally broke the surface of the water, his lead was half a body length. When he touched the wall, with Held in next, he had turned in the fastest 100 free split of his career — 47.12 seconds. The Americans’ lead, over Australia at the moment, was nearly a second.

Did he know he had that in him? “Yes,” was Phelps’s simple answer.

So the event built to Adrian’s anchor leg, just as the night built to the relay — which came last. Yet even before that race, there were moments that resonated in vastly different ways. When Vollmer gave birth to a son last year, she was already a decorated Olympian, four times a gold medal winner, including in the 100 butterfly four years ago in London. But she decided to come back and try for the Rio Olympics at 28.

“I didn’t know if I was going to get here or not,” Vollmer said.

She did, and she was a key member of the American women’s 4x100 relay team that took silver Saturday night. Sunday was all about her own pursuit, though — the 100 fly, again. She had no real shot at taking down Sjostrom, who broke her own world record in 55.48 seconds for gold. She fought to keep up with Canada’s Penny Oleksiak, who took silver. When she touched in 56.63, she whipped her head around: bronze.

“I feel like I’m more appreciative of every single moment that I have out here,” Vollmer said. “. . . Like a personal gold for me.”

There was, too, the specter of Russia’s Yulia Efimova, who had been originally banned from these Games in the wake of the widespread doping scandal that engulfed her country, back in the pool. Efimova won her semifinal heat of the 100 breaststroke and extended her index finger — No. 1. American Lilly King, whose time in the other semi beat Efimova’s by two-hundredths of a second, shook her finger at the television screen — which was caught by cameras.

“You’re shaking your finger ‘No. 1,’ and you’ve been caught for drug cheating,” King told NBC. “I’m just not a fan.”

The fans, then, are Phelps’s. Held, an Olympic newbie, did his job in handing the lead to Adrian, who followed with the night’s fastest leg — 46.97 seconds. So it was left to Phelps to perform a newer part of his job, coaching the kids on how to act on the medal stand.

“I kind of told them beforehand,” he said, “‘it’s okay to sing, and it’s okay to cry.’”

Phelps held back his tears. He has more races this week, including three individual events. He has already carried the American flag into the Opening Ceremonies. And when Phelps walked across the pool deck, his 19th gold medal draped around his neck, Adrian asked him if he might do this again, that familiar sight every fourth summer.

“I said, ‘Sorry, bro,’ ” Phelps said. “You guys got this. I’m out.’”

But not till the end of this week. And not till, it appears, more medals are won.